IL1B and juvenile idiopathic arthritis: It failed, but proved highly successful in cryopyrin-associated periodic syndrome (CAPS), systemic-onset JIA, and other disorders caused by overproduction of IL-1β.45 The pediatric rheumatology research networks Pediatric Rheumatology Collaborative Study Group (PRCSG) and Paediatric Rheumatology International Trials Organisation (PRINTO) praise US/EU pediatric legislation as responsible for today’s massively improved treatment of JIA.43 The reality is more complex.